Author(s)

B. Dolinar & H. Vrecl-Kojc

Abstract

This paper deals with the suspended load in the Sava River, which is the longest river in Slovenia. It flows for 220.7 km across a geologically, geographically and climatologically agitated area. The river supports a considerable electricityproduction potential. Besides the existing power plants, there are several hydroelectric plants under construction, of which \“Boštanj” has just begun its production of electricity. The objective of the study described in this paper was to determine the concentration and composition of the suspended load in the reservoir of the hydroelectric power plant Boštanj. For this purpose, 24 water samples from the area of the water intake and the water outlet were taken. At the same time the flow rate of the river was measured. The solid particles were removed from the water with the help of sedimentation and, in the final stage, with water evaporation. With such an approach, a sufficient quantity of suspended material for further mineralogical and chemical analyses was ensured. The analysis showed that the quantity of the suspended load, for the same flow rate, was larger at the water intake than at the water outlet. The difference represents the material that sedimented in the lake due to the speed decrease of the water as a result of the river’s impoundment. The sedimented material may be expressed in relation to the flow rate. A comparison of the structure of the samples from both sampling areas showed that at the water outlet there is a somewhat smaller share of carbonate grains and heavy minerals than at the water intake, and a higher content of organic detritus and clay particles can also be observed. Keywords: suspended load, sedimentation, sediment transport, water storage reservoir.

Keywords

suspended load, sedimentation, sediment transport, water storage reservoir